The Pet Shop Boys will mark their upcoming performance at classical music spectacular The Proms by calling for an official pardon for men who were imprisoned before homosexuality was legalised in the U.K.

The West End Girls hitmakers are to unveil their orchestral work A Man From The Future on 23 July (14) as part of the prestigious, eight-week long event in London.

One track, called The Pardon, tells the story of Alan Turing, who was posthumously pardoned over his 1952 conviction for gross indecency because he was in a relationship with a teenage male.

The pop duo is planning to use the platform at The Proms to call for similar pardons to be issued to thousands of other gay men who were arrested over their sexuality before British law changed in 1967.

Singer Neil Tennant says, "So very many lives were ruined over such a long period. Frankly it rather disappoints me that (gay rights pressure group) Stonewall has not done more. So we're making the statement ourselves."